Agronomic Update – June 26, 2020

Fun Fact:  It takes 91 gallons of water to produce one pound of corn….that’s roughly 5,000 gallons per bushel!

Topics for this Update:

  • GDU Accumulation,  current and future weather conditions
  • What’s going on in my fields right now….what’s next….
  • Insect Update
  • Soybean Update
  • Granular Insights Imagery

GDU accumulation & Weather Conditions:

As of June 25th, we have accumulated approximately the following for Growing Degree Days in 2020:

Planting Date     GDD’s 2020         Average GDD     Departure from average

April 21                 945                          930                                      +15 (+.5  day)

April 26                 925                         894                                       0

May 1                     841                         853                                        -12 (-.5 day)

As you can see we have gained some ground versus last update from two weeks ago.  We are currently tracking normal for plant development.

The above maps are showing the 6-10 day and 8-14 day temperature outlooks and the 8-14 day precipitation outlook.  These forecasts are indicating a warmer than normal trend into the first 10 days of July with precip outlook about normal.  This will spur rapid elongation by the plant, and if forecasts turn out as predicted, we will continue to trend normal to slightly above normal for GDU accumulation through this period.

What’s Going On in My Fields Right Now….and What’s Next….

  • Much of the corn crop is in the 9-11 leaf stage right now.
  • At this stage, the tassel is beginning to develop rapidly now and the stalk is continuing rapid elongation.
  • Stalk elongation occurs through the elongation of its internodes.  Next few weeks will see peak susceptibility to green snap….
  • By V10, the time between the appearance of new leaf stages will shorten, generally occurring every two or three days…or approximately a leaf for every 50 GDU’s.
  • In the above forecasts, we will be accumulating 25-28 GDU’s/day, so expect a new leaf potentially every couple of days.
  • At V10, the corn plant begins a rapid, steady increase in nutrient and dry weight accumulation which will continue far into the reproductive stages.
  • Soil nutrients and water are now in greater demand to meet the needs of this increased growth rate.  Keep this in mind as you think about your total N applied so far and what future needs will be….
  • Kernels per row begin around V12 and continue through and up to tassel stage….’just around the corner’….
  • Greatest yield loss from moisture stress occurs from two weeks prior to, to two weeks after tassel.  With current weather conditions and forecasts, the great majority of the crop will most likely be tasseling the week of July 13th.  This will depend upon hybrid and planting date of course.  GDU’s to silk run from 1280 – 1450 depending upon hybrid.  If forecasts turn out to be true, GDU accumulation over the next two weeks will be approximately 360-400 GDU’s….add this to 900 and we will reach 1250-1300 GDU’s by July 9th…..tasseling beginning or ‘just around the corner’ from there.  Bottom line, water needs will be greatest over the next month.
  • The main nodal root system is developing with the last (5th) nodal root developing quickly now.  Brace roots will develop over the next couple of weeks.  See video for root development and moisture…..IMG_0178
  • Waterhemp/Palmer amaranth control in corn is much more erratic this year.   We continue to see re-growth from sprayed plants.  See photos:
  • We are seeing this in fields that have Status or Diflex add to heat up spray tanks.  The heat and wind of the past few weeks has played a role in what we are seeing as many of these plants most likely ‘hardened off’ in the heat and dry conditions at the time of application.

Insect Update:

  • So far seeing very little activity from European Corn Borer
  • Plan on scouting just prior to tasseling for Western Bean Cutworm.  We will have pheromone traps out once again to monitor flight activity.  Check back on our website for updated counts.
  • Still seeing some Thistle Caterpillar in soybeans, but overall pressure is significantly down form 2019.  Keep monitoring for this pest.
  • Should be scouting now for Corn Rootworm larvae.

Soybean Update:

  • Much of the soybean crop is in the beginning R1 (Beg. flower) to full R1 stage.
  • R1 is the timing for any White Mold treatments.  To get effective control on white mold, treatments NEED to go on at R1, with a follow up at R3.  Treatments should be going on now, or over the next week.
  • We are seeing a lot of leaf-cupping in the soybeans.  This is occurring in almost all fields….with or without pre-emerge herbicide applications….with or without dicamba applied.  I still feel like this is mostly environment related….high temps and wind.  So far I have not found any common denominator.
  • Water needs by soybeans begin to rapidly increase at R1 and reach peak at R3 (Beg. Pod).

Granular Insights Imagery…

  • Please contact us if you would like to receive the satellite imagery from Granular Insights.  This is a great tool for scouting purposes.

Thanks for your support!!

 

 

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Agronomic Update – June 12, 2020….

I think this is a pretty apt description (among others!) for how the year of 2020 has gone.  It’s been a mess in more ways than one.

Topics for this Update:

  • Temperatures and GDU accumulation.
  • What’s going on in my fields right now….
  • Granular Insights & Imagery

Temperatures and GDU accumulation:

As of June 11th, we have accumulated approximately the following for Growing Degree Days in 2020:

Planting Date     GDD’s2016          Average GDD     Departure from average

April 21                 630                          645                                      -15 (- 1 day)

April 26                 577                         610                                       -33  (-2 days)

May 1                     526                        570                                        -44 (-3 days)

Even though we have had heat as of late, we continue to be behind in GDU’s compared to normal.  This shows  how much ground we lost from the very cool May.  The average high temp for May was 8 degrees below normal and the average low was 3.5 degrees below normal.  This goes along way to explaining why, even though our crop was in much earlier than normal, we are still behind and why our stands are somewhat erratic and uneven….however, most stands actually turned our much better than first anticipated at the end of May!

The above photos show the impact of residue on crop emergence and unevenness.  In the left photo, you will see a spot in the field where the plant height drops versus the rest of the field.  This area had more soybean residue and the trash wippers did not do as a good a job moving the residue….as you can see in the other two photos.  Where the residue was moved from the row, the stand is very good and even….where the trash was not moved as well the stand is good, but delayed and more uneven.

These two photos are from the same field (end rows) looking in the same direction.  The first photo was at V1 stage and the second is at V6 (taken June 12th).  The main thing to notice here is the row where the stand is missing and comparing that to the second photo.  Notice how well the row eventually filled in from the second photo.  In the first photo, the seed soil contact was very poor as the soil was very loose and very dry.  The plants in the filled in row are only 1 leaf stage behind.  Just a curious observation!

The above pictures are the 6-10 day temperature, the 8-14 day temperature, and the 8-14 day precipitation forecast maps.  After this upcoming few days of heat, it looks like we will have a cool spell.  This will make it harder to gain any ground versus normal GDU accumulation.  It also means that we could potentially see rapid growth syndrome in the corn as we move through the month of June.  See link below for more info.

https://www.pioneer.com/us/agronomy/rapid_growth_syndrome_corn_cropfocus.html#:~:text=Rapid%20growth%20syndrome%20occurs%20when,acceleration%20in%20plant%20growth%20rate.

What’s Going On in My Fields…..

Overall much of the corn crop looks good.  The majority of the crop is in the 6-7 leaf stage-of-growth depending upon planting date.   From V1-V10, corn gains a leaf collar about every 83 GDUs.  From V10-VT, corn gains a new collar every 50 GDUs, or about every other day.

  • At V6, the growing point and tassel are above the soil surface and the stalk is beginning a period of greatly increased elongation.
  • The growing point is above the ground, so major hail at this point can cause some serious damage
  • You can find a tassel by dissecting the plant
  • The primary ear will usually be located at node 12,13, or 14
  • Determination of potential kernel rows around will be completed around V7 (range of V5-V8)…we are currently at this stage!
  • Kernels per row begin around V12 and continue through and up to tassel stage
  • Nitrogen needs will continue to grow through tasseling and into early reproductive stages.  Nitrogen uptake in corn is now increasing rapidly and will stay that way through tassel (up to 4-8 lbs per day).  Remember that today’s hybrids use nitrogen later in the growing season and into the reproductive phases.  You will want to keep that last shot of N available for after tasseling.
  • We are now heading into the rapid growth and accumulation of dry matter by the plant.  The window for brittle snap will start to grow exponentially over the next few weeks.
  • Watch temperatures as you are spraying post-herbicides on corn or beans over the next several days.  When temps are in the 90’s and humidity is low, the potential for crop response from post-application of herbicides will increase.  It is not recommended to be spraying during the heat of the day if temps are in the mid-upper 90’s…both for potential crop response and herbicide control.

Granular Insights and Imagery

The above photo is a screenshot of a June 10th satellite image from the Granular Insights app.  Corn is on the top half of the photo and soybeans are on the bottom half.  One can readily pick up the soybean plot that is planted in this field from the blue strip to the left of the image.   Granular Insights imagery is now ‘live’ and running with a new image showing up every 1-3 days.  This imagery is an excellent scouting tool as well as diagnostic tool.   Many growers already qualify for this imagery.  Please contact us to get you set up on using this new tool from Pioneer and Granular.

Thanks for your support!  Stay safe and healthy!

 

 

 

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